Tetracyclic pyrazine-fused furazans as insensitive energetic materials: syntheses, structures, and properties

Energetic compounds with fused tetracyclic backbones were synthesized and fully characterized, and their structures were confirmed by single crystal X-ray diffraction. Changes from nonplanar to planar structures led their densities to increase from 1.800 to 1.856 g cm⁻³ (298 K). Hydrogen bonds and π–π interactions were analyzed to understand this phenomenon. Energetic evaluations showed that compounds 2 and 3 detonated with performance comparable to TATB. Excellent mechanical sensitivities (IS: >40 J; FS: >360 N) indicate the promise of these furazans as insensitive energetic materials.